Hi mikez.
You are wise to be skeptical about the “bio-based” memory foams as this is in most cases more about marketing and it is also somewhat misleading because the polyfoam and memory foam are still mostly petrochemical based … not “bio-based” … These foams have only a very small part of the petrochemical polyols (one of the chemicals used to manufacture polyfoam and memory foam) being replaced with plant oil … hence “bio”. You can see some more comments about “so-called” bio-based or plant-based foam materials in post #2 here
As stated many times on our site, regardless of the name used for the foam, you’d always want find out information listed here and the exact specifications (such as foam density) and the quality of the componentry in the mattress so that you can compare it to the durability guidelines here. Also Post #2 here has some guidelines (including MF safety/certifications) to keep in mind when purchasing any mattress that contains memory foam.
Phoenix